The Sweettruss Varia Corner (KV4/290-VC) can now be rotated with precision to match dedicated angles of 22.5°, 45°, 67.5°, and 90°.
Simply doubleclick on the moving part and rotate it approximately. Then move it into position and it will automatically snap to the nearest preset angle, as indicated by the Z Rotation values in the Selected Items Properties panel on the right.